Once upon a time 715 million years ago: Venus could be habitable long enough for life to emerge

 

It is remembered that once the Greek philosopher Empedocles of Acragas, in the 5th century BC, said that Venus was a habitable planet with life forms similar to men and women, with other diversities of animals. The truth is that apparently he was not so wrong and modern science seems to give him the reason that there was once life there. For 2,000 to 3,000 million years after its formation, Venus may have maintained a habitable environment, long enough for life to emerge on "Sister Earth." Five simulations were created that considered what the environment of Venus would look like based on different levels of water cover. This consisted of adapting a 3D general circulation model that took into account changes in atmospheric compositions and the gradual increase in solar radiation as the Sun warmed throughout its useful life. In three of the five scenarios, the topography of Venus was very similar to the current one, the ocean oscillating between a minimum depth of 10 meters and a maximum of approximately 310 and a small amount of water was trapped in the ground. They also considered a scenario with Earth's topography and a 310-meter ocean, and another where Venus was completely covered in a 158-meter ocean. In the end, all five simulations indicated the same thing: that Venus would have been able to maintain stable temperatures, from a low of 20 degrees Celsius to a high of 50, for roughly 3 billion years. If it weren't for a series of events that caused the reconfiguration of 80 percent of the planet's surface (leading to outgassing of the CO2 contained within the crust), it might even be habitable today. 715 million years ago the atmosphere would have been similar to Earth.

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By: Alejandro Sebastián Von Heguer, National University of Lomas de Zamora, Buenos Aires. Source: European Planetary Science Congress (EPSC-DPS) by Michael Way and Anthony Del Genio of NASA's Goddard Institute for Space Science (GISS).